What is acute bronchitis?

March 2001

---Philip A. Brunell, MD

How many times have you told parents that their child had "bronchitis?" What did you consider to be "bronchitis?" What treatment, if any, was prescribed?

It was not uncommon for me to have young children brought in with a very disturbing cough lasting several days or longer often following an upper respiratory illness. Was this bronchitis? We really did not learn very much about this during our training and probably for good reason. Just for fun, look up bronchitis in the textbook of pediatrics on your office bookshelf. I went to the library to check this out and was surprised by the absence of its presence.

The best discussion of bronchitis among the few I could find was in Oski's Principles and Practice of Pediatrics. The authors separate acute from chronic bronchitis, the latter lasting more than three months. Others have a one-month cut off. My guess is that many children presenting with disturbing cough are diagnosed as having sinusitis and sent home with an antibiotic for 10 or more days. Others might be treated as reactive airway disease, wheezy bronchitis or given some other similar label and sent home with a prescription to treat an allergic condition.

What about pertussis?

The one diagnosis that we probably do not think of very often is pertussis - at least during the beginning of the illness before a whoop develops or emesis is associated with coughing. Can this occur in kids who have had pertussis vaccine? It certainly can. Pertussis vaccine, although very effective, has the highest failure rate of any of those given routinely. It is generally believed that the vaccine is better at preventing whooping cough than preventing infection. In an ongoing study of adults with cough more than five days, pertussis was identified in a small but significant percentage. This is thought to be due to loss of vaccine-induced immunity. However, it is unclear how often this occurs in the pediatric age group.

Pertussis provides a useful paradigm for a special type of reactive airway disease. It has been well recognized that after infection with Bordetella pertussis, children may have a "tight semiparoxysmal cough for some weeks after the vomiting has ceased and many children apparently develop the habit of whooping with any cough" (Common Contagious Diseases, Stimpson and Hodes). These episodes are often precipitated by viral infections and may occur for more than a year following pertussis. This infection appears to produce a "reactive large airway disease," which I will refer to as RELAD. It is possible that some other viral or bacterial infections may produce RELAD, which we call bronchitis, sinusitis, or reactive (small) airway disease.

It is of interest that the recurrent paroxysms following whooping cough are described as possibly being a "habit." Can bronchitis be a behavioral manifestation of respiratory infections in some individuals?

1.8 million episodes

In the Oski section, it is noted that "in 1989, the National Health Interview survey estimated that 1.8 million episodes of acute bronchitis occurred in American preschool children alone." In an office-based study done several decades ago, bronchitis, which was characterized as "deep cough and rhonchi audible in the larger airways," occurred in almost 7% of children during the second year of life (Am J Epidemiol [1981]114:786). Thus, whatever acute bronchitis is, it certainly is being diagnosed frequently.

Children who are brought in because of cough must be evaluated to determine their management even if we have difficulty assigning a diagnosis. A cough is common to all of these children. Signs of upper respiratory infection are usually present together with transmitted rhonchi. Fever is a variable sign and when present is usually low grade. There may be lassitude, which can be secondary to loss of sleep, fatigue from severe cough or decreased oral intake. Roentgenographic studies are rarely indicated unless one has reason to suspect a foreign body, tuberculosis, cystic fibrosis or another conditions which might be responsible.

What then should our management be? In preschool children, antibiotics are rarely indicated. They may be useful if pertussis or parapertussis is suspected. In older children, particularly those with productive coughs and low-grade fever, one might suspect Mycoplasma pneumoniae or Chlamydia pneumoniae as the etiologic agent. In some of these cases, appropriate antimicrobial therapy may be indicated. However, antimicrobials are not likely to have a dramatic effect on the cough, even if it is due to Bordetella.

Cough needs suppressive therapy

The management of cough is paramount. This, after all, is the reason for which the parent sought help. However, it is useful to determine whether the cough is disturbing to the child or to the parent or to both. A cough that interferes with sleep or obtaining adequate nourishment needs suppressive therapy. If there is smoking in the household, it might be a good opportunity to reinforce the need to address this issue. The humidity of the household should also be assessed, particularly in children who have evidence of living in a dry environment, eg., nummular eczema, crusted nasal secretion, etc. Providing a humid environment during sleep is not intrusive, it gives the parents something to do (other than giving an antibiotic) and it probably will do some good. Demulcents, in the form of lollipops, are one of my favorites. Finally, effective cough suppression at bedtime, if cough interferes with sleep, or prior to meals if the cough causes vomiting, certainly is indicated.

Bronchitis appears to be a commonly diagnosed condition in children, although the criteria are not entirely clear. It is likely that many receive antimicrobial agents despite that they are rarely indicated. How antibiotic use for this condition contributes to growing antibiotic resistance is unknown.